I'm editing a wedding as I always do, and now the audio and video are stuttering! It seems like all of a sudden the ram can't keep up. When it's rendered, it's all good, but in the edit window it's really (annoyingly) sputtering
a - You recently installed a program that runs in background and is sucking up all of your resources
b - You recently installed a virus
c - System is overheating (open it up and clean it)
d - A system component died / is dying
e - Hard drive(s) fragmented / failing
What version of Vegas are your running?
What are you doing differently this time? If nothing, then start with (a -) above
2. Open Vegas. Put one event on timeline. Preview that . OK? That will tell you if there is some project setting that has been tweaked (e.g., opacity).
3. Video on external drive? If so, copy a few files to your internal drives, and try #2 above. That will help you narrow the problem down, and troubleshoot appropriately.
4. If you suspect a virus or some other program in the background, open Task Manager (Ctrl-Alt-Del) and on the process tab, sort by CPU and see if some process, other than Vegas is hogging the CPU.
5. Free disk space? Bad things happen when you only have 1% disk space left.
I have had this a few times suddenly with my old notebook and footage imported from camcorderdisc, but after a reboot, like John says, it's ok. I my case it might also have to do with that I'm walking on the edge with this footage og 512 MB RAM and PentiumM 1.6 GHz.
If it happens when you are in the middle of an edit and not at the very beginning, it very well can be an over heating hard drive. If it is the HD, cool it down and the problem will be solved unless the HD is damaged.
Another problem with the system disk besides overheating that reflects your description is a badly frag system pagefile. Rebooting can help, but cleaning up the temp and internet files then defrag the system drive or the drive where you have the system pagefile will improve performance. A disk with heavy frag files, especially video files, lib effects files, etc will kill performance. Of course, as stated in early posts, virus or adware can kill performance.
another issue is if your using ASIO drivers with a soundblaster card set to 44.1 (as opposed to 48khz)
Th erealtime conversion of variable bitrate and samplerates can be handles by the Soundcard HW without an issue, but windows sometimes nukes the drivers.
This is mainly for HDV stuff with MPG audio, as the audio itself is converted on the fly (by the soundcard)